Illuminating unit



Dec. 30, 1947. w, GARSTANG 2,433,690v

ILLUMINATING UNIT Original Filed Ju1y'26, 1941 ENTOR. /4 4MM ikea-mag Patented Dee.` 30, 1947 ILLUMINATING 'UNIT William W. Gar-stang, Indianapolis, Ind., assigner to Electronic Laboratories, Incorporated, Indianapolls, .lnd., a corporation of Indiana Original application July 26, 1941, Serial No.

404,145, now Patent No, 2,337,745, dated December 28, 1943.

Divided and this application September 24, 1943, Serial No. 503,615

I'Clalml.l (Cl. 176-422) The present invention relates to improvements in illuminating units.

More particularly, the invention relates to a type of lamp unit for emitting what has been commercially designated as a black light.

In certain types of illumination as, for instance, in cockpit illumination of airplanes and the like, it is desirable and in numerous instances essential. that while the instruments be visible to the pilot, there be present in the cockpit no apparent source of light. It has' been found that light rays which would ordinarily not only illuminate the instruments but also illuminate the cockpit, have a tendency to distort the pilots vision during night flying and after he has been looking into darkness ahead for a considerable length of time. As la result of this condition, there has been developed a so-calied "black light through the medium of which the instrument indicators, which have been colored with a fluorescent material, may be illuminated by ultraviolet or near ultra-violet rays developed byl a lamp which ultra-violet or near ultra-violet rays are not visible to the eye.

The present invention relates to a lamp unit having the above characteristics.

It has for one of its objects that -of providing a compact lamp unit capable of .emitting ultraviolet or near ultra-violet rays and capable of.

Fig. 2 is a longitudinal sectional view of they lamp unit embodying my invention.

Fig. 3 is a side elevation ofthe unit shown in section in Fig. 2v.

Referring to the casing structure illustrated in Fig. 1, there is provided a tubular casing I which may be formed of metal, preferably of aluminum,-

for lightness. This tubular casing I is provided on one side with a cutout section or opening 2 which provides a view opening in the casing. Mounted within the casing I, at one end, is a hollow plug 3 which telescopes the end of the casing and makes a snug fit therein. This plus f is provided with a hollow stem 4 screwthreaded i on its exterior as at 5 to receive a supporting bracket 6 andthe clamping screws 1 and 8 for maintaining the bracket in position. The interior` y fingers adapted to surround the cylindrical porl of the stem 4 is provided with an insulating busnf ing 8 and within this bushing is fitted a contact plug I0 having a spring contact Il capable of tion I4 of a rotatable cap having a closed end I5. This cap is provided with an annular groove I6 capable of receiving an annular bead IIy in the spring fingers formed at the end of the casn ing whereby when the cap is telescoped in pov sition, it will be held against longitudinal disf placement while permitting rotation thereof.

'I'he unitary illuminating unit is mounted within the above described casing. This unit comprises a shell I8 which may be formed of insulating material and hasits ends closed by end caps I9 and 20. Contact studs 2| and 22 extend through these end caps, the stud 22 being adapted to contact the contact I2 andthe stud 2| being Y adapted to make electrical contact with the interior of the closure cap rotatablyv` mounted on rescent tube type.

the casing, which casing may be grounded. This tubular shell likewise is provided with an elongated slot or view opening 23 in one portion thereof and with a series of view openings 24-24 gradually diminishing in size.

Mounted within the shell I8 is a lamp comprising a bulb 25 with insulating end sleeves 26 and 21 and mounted within the end sleeve 2l is astarting switch 28. This lamp bulb 25 is of the fluo- The glass of the bulb, however, may be formed of material which, while permitting the vpassage there through of ultraviolet or near ultra-violet rays is impervious to the passage of visible light rays.

If desired, the interior of the glass bulb may be coated with a fluorescent material capable of regenerating the ultra-violet rays developed by l the lamp and converting these ultra-violet rays into visible and near ultra-violet rays which near ultra-violet rays are invisible to the eye. However, due to the characteristic of the glass of :naanoo which the bulb is formed the near ultra-violet rays will be passed therethrough. The lamp bulb contains the usual quantity of mercury and the usual heaters 29-29 for heating or ionizing the mercury for the provision of a mercury arc to develop the ultra-violet rays. At each end of the lamp bulb, there is provided a pair of contacts, one of which at one end ls connected with the contact 2| and the other of which, at the same end, is connected through a suitable 4conductor 30 with one terminal of the starting switch. The opposite terminal of this starting switch is connected to one contact, at the opposite end of the bulb. and the other contact at the same end is connected to the terminal 22.

This bulb, as is illustrated in Fig. 2, is mounted Within and rotatable with the shell I8 which is preferably formed of material impervious tothe passage of any light rays. This shell is provided with a. lug I8' adapted to flt within an elongated slot 3| in the sleeve portion I4 of the cap so that the entire casing is capable of rotation with this cap. The contact 2|, as before stated, makes contact with the cap and through the cap and casing I is grounded for the completion of the lamp circuit.

Theabove described illuminating unit thus provides a compact self-contained unitary structure which may be inserted in the casing shown in Fig, 1 andwhich may be quickly and easily replaced when worn out. It is obvious that'when the slot 23 in the casing I8 coincides with the slot 2 in the casing I, a maximum passage of the near ultra-violet rays developed by the lamp is permitted. For changing the intensity of the rays emitted by the lamp, the casing I8 may be rotated through the medium of the rotatable cap to cause the openings 24, of various sizes, to coincide with the slot 2 in the casing to thereby permit the passage of light rays of various intensity. I have heretofore referred to ultraviolet and near ultraviolet rays and it will be understood that where I have used the term .ultraviolet," in certain of the appended claims, such a term comprehends the near ultraviolet rays as well. y

This application is a. division of my co-pending application, Serial No. 404,145, led July 26, 1941 eventuating in United States Letters Patent No. 2,337,745, dated December 28, 1943.

I claim:

1. An illuminating unit comprising in a selfcontained unitary structure, an elongated open ended shell impervious to the passage of light and having a, plurality of openings in the walls thereof extending longitudinally thereof and varying in size circumferentially thereof, an insulating cap at each end of said shell closing said open ends, a contact terminal mounted in each of said caps and a fluorescent lamp bulb mounted within said shell in xed relationship therewith and having contact terminals at its opposite ends connected with the contact terminals in said end `caps, said bulb and its contacts being wholly mounted within and enclosed by said shell,

2. An illuminating unit comprising in a. selfcontained unitary structure, an elongated open ended shell impervious to the passage of light and having an opening in the wall thereof extending longitudinally thereof, an insulating cap at each end of said shell closing said open ends, a contact terminal mounted in each of said caps, a uorescent lamp bulb impervious to the passage of visible light rays mounted within said shell in fixed relationship therewith and having 4 contact terminals at its opposite ends connected with the contact terminals of said caps. said bulb and its contacts being wholly mounted within and enclosed by said shell. l y

3. An illuminating unit comprising in a selicontained unitary structure, an elongated open ended'shell impervious to the passage of light and having a plurality of openings in the wall thereof extending longitudinally thereof and varying in size circumferentially, an insulating cap at each end of said shell closing said open ends, a con- .tact terminal mounted in each of said caps and a fluorescent lamp bulb capable of transmitting ultra-violet light only mounted within said shell in ilxed relationship therewith and having contact terminals at its opposite ends connected with the contact terminals in said caps, said bulb and its contacts being wholly mounted within and enclosed by said shell.

4. An illuminating unit comprising in a selfcontained unitary structure, an elongated open ended shell impervious to the passage of light having an elongated opening in the wall thereof extending longitudinally thereof, an insulating cap at each end of said shell closing said open ends, a contact terminal mounted in each of said caps, a fluorescent lamp bulb mounted within said l shell in fixed relationship therewith and having a contact terminal at its opposite ends connected with the contact terminals in said end caps and a starting switch for the lamp of said bulb mounted within said shell and operably connected with said lamp, said bulb and its contacts being wholly mounted within and enclosed by said shell.

5. An illuminating unit comprising in fa selfcontained unitary structure, an elongated open ended shell impervious to the passage of light having a plurality of openings in the wall thereof extending longitudinally thereof and varying in size circumferentially, an insulating cap at each end of said shell, a contact terminal mounted in each of said caps, a fluorescent lamp bulb mounted within said shell in xed relationship therewith and having Contact terminals at its opposite ends connected with the contact terminals in said caps and a starting switch for the lamp of said bulb mounted within said shell and operably connected to said lamp, said bulb and its contacts being wholly mounted within and enclosed by said shell.

, 6. An illuminating unit comprising in a sel!- contained unitary structure, an elongated open ended shell impervious to the passage of light, a portion of said shell being open longitudinally thereof, an insulating cap at the end of each end of said shell closing said open ends, a contact terminal mounted in each of said caps, a fluorescent lamp bulb mounted within said shell in fixed relationship therewith and having a pair of contact terminals at each end, one of each of said pair being connected to the contact terminals in said caps, an insulating cup receiving one end of said lamp bulb and a starting switch for said lamp bulb mounted in the bottom of said cup and having a pair of contacts, one of which is connected to one of the pair of contacts at one end of said'bulb and the other of which is connected to one of the pair of contacts at the opposite end of said bulb, said bulb and starting switch being wholly mounted within and enclosed by said shell.

WILLIAM W. GARSTANG.

(References on following page) 2,305,583 Hodgkins Dec. 15, 1942 10 6 Name Date Prouty Sept, 21, 1937 Lew Nov. 10, 1942 Zecher 01st, 10, 1933 FOREIGN PATENTS Country Date Germany Jan. 18, 1926 Great; Britain Aug. 20, 1936 

